Patent GB-741039-A (GB)
Title: Calculating machine
IPC: G06C7/10
Filed: 1953-12-29
Abstract: 741,039. Calculating-apparatus. NATIONAL CASH REGISTER CO. Dec. 29, 1953 [Feb. 10, 1953], No. 36047/53. Class 106 (1). In a ten-key calculating machine with a laterally-movable pincarriage, the latter receives a substantially complete denominational step-shift on depression of any amount key and, for actuating the pins, each key-stem carries an interponent movable relative to the stem to permit lateral movement of the corresponding pin of next lower order when the key is depressed. A machine cycle may be initiated by depressing an amount key beyond the pin-setting position. The invention is applied to the machine described in Specification 693,659 with the initiating mechanism described in Specification 710,318, the full keyboard being replaced by the present setting mechanism. Setting mechanism. The keyboard frame comprises side plates 122, Fig. 4, and is supported on a shaft 134, which also supports the totalizer frame, and on a stud 135 at each side. The ten keys are depressibly mounted in a pan 136 and have cranked stems, which co-operate with a common bail 137 and the ends of which are aligned and, except in the case of the " 9 " key, carry pawls 139 for actuating the setting pins 67. The pins 67, Fig. 9, are slidable in the laterally-movable carriage 60 and have notched edges for co-operation with detent springs 70. As a key is depressed, a depending finger 156, Fig. 10, of the bail 137 rocks one, 97, of a pair of co-operating escapement pawls 96, 97 which engage the notched front edge of the pincarriage. The carriage is urged to the left by a spring and the arrangement is such that as soon as the corresponding pin 67 has been depressed, the carriage step-shifts to its next denominational position, the movement which occurs when the key is released being small and ineffective. The carriage is slidable on a shaft 86 and carries a roller 87 running in a raceway 88. Each pawl 139, Fig. 9, is normally held in the position shown by the engagement of its shoulders 146,147 with the pan 136. However, when the key is depressed, the pawl is free to rock clockwise as, during the step-shift of the carriage, the corresponding one of the next row of pins moves beneath the key-stem. The pawls also enable restoration of the carriage to the right, during which a cam plate 72 restores set pins, even if a key is held depressed. The carriage carries a calibrated bar 66 visible through a window in the keyboard frame to indicate the denominational position of the carriage. A sliding key 18 has an extension 168 which engages a projection on the carriage, when the key is moved to the right, to restore the carriage and consequently any set pins. The carriage is restored at the end of a cycle by a lever 111, Fig. 13, co-operating with a pin in the carriage and rocked by a link 115 having a hook 116, engaged by a stud 119 in a camcontrolled plate 120. As the movement is completed, a cam surface 117 in the link 115 rides on a stud 118 to disengage the hook 116 from the stud 119. Differential mechanism. During a machine cycle following the setting of a complete item, stop bars 36 are differentially positioned under the control of the set pins. In a given denomination, the pins set by the " 1 " to " 8 " keys co-operate with a tooth 76 of the stop bar and the pin set by the zero key with a tooth 74. No pin is projected by operation of the " 9 " key and so the stop bar is, in this case, free to move until a surface 85 engages a fixed comb 35. A bail 84 is carried by the carriage and extends to the left where it is engaged by surfaces 91 of the stop-bars, which are thereby permitted the single step of movement necessary to register zero. The bail 84 is lifted by a bail 92 in total operations. A cam-controlled bail holds blades 51 against ratchet teeth 49 carried by the stop bars during the first part of the cycle to prevent rebound. Repeat mechanism. The rocking of a repeat lever 23, Fig. 13, clockwise lifts a stud 132 in a lever 130 and consequently rocks the link 115 so that its hook 116 is out of the path of the stud 119. Thus, in an ensuring machine cycle, the pin-carriage will not be restored. Starting mechanism. On depression of any amount key beyond the pin-setting position, the finger 156, Fig. 10, of the bail 137 acts, through a stud 101 in the pawl 97 and against a spring 161, to close a micro-switch 107. A solenoid 31 in series with the switch 107 is thus energized and, in known manner, rocks a lever to initiate an add operation. The lever allows a normally-closed micro-switch 158, also in series with the solenoid, to open so that at the end of the cycle, the lever may be restored and the motor de-energized. If however, the amount key is held fully depressed, a further cycle will be initiated. A manually-operable switch 25 enables this initiating mechanism to be rendered ineffective. Operations may, in any case, be initiated in known manner, by function-control keys.